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L. A. BROWN AUTOMATIC CUT-OVER AND SAFETY SWITCH Filed March 1927 2 SheetsSheet 1 11 II I! H I I l :l U

Witnesses.- q M 4 173002250; 140a,? LX4N0E E0 M77 4/5 ffamey Dec. 13, 1927.

- L. A, BROWN AUTOMATIC CUTf-OVER AND SAFETY swncu 2 Sheets-Sheet 2 Filed March 1927 Wimesses:

Patented Dec. 13, 1927.

PATENT- OFFICE,

LADURA ALEXANDER BROXV'N, C-F UNIONTOWN PENNSYLVANIA.

AUTOMATIC CUT-OVER AND S AFETY SWITCH.

Application filed March 16, 1927.- Serial No.- 175,823.-

This invent-ion relates to automatic cutover and safety switches foruse-in -controlling two sources of electric current-i to a single motor, and while not limited thereto, relates more particularly to switches of this class particularly designed for use on mine locomotives and similar machines which have a trailing, cable and trolley for connecting with the source of supply.

The object of this switch is to automatically 'cut-over or'transfer from=one-source of current supply to the otherand to prevent the 'cuttingover otj one source 'while the other sourceisin use. .:s 7 At the present time a hand -operatedswitch is generally in use to cutover from one source ofcurrent supply to=tbe;-other.o n

'- mine locomotives;andsuch -switches are often operated intentionallyand accidentally by the operator with a load o'n-the motor; which causes considerable are at the switch contacts; This arcing many times seriously. burns the-operator oroauses himtoj'ump from the locomotive'which also= many times results in serious injury.-

The present switch is completely enclose-:1 in a fiame proof box as a protection against an'y'arc accidently formed, and is-electricallyinterlockedjso that the switch can-not opera ate until the 'current is removed-from the main cont-acts 3 1 Y -In'the drawings'- 'Figure lis a side elevation 'of wswitch constructed 'in' accordance with this inven-- tion, -with the cover plate removed for clcarnessf Figure 2 isan end elevation-with in' 'omitted for clearnessi igure 3 is a diagram ot the circuits ma le= by the switch of Figures 1 and 2. Referring more particularly tO tlle draw ings, the numeral 2 designates the casing, of the switch as a whole, which may be composedof metal or other fire resisting material and entirely encloses the switch. -An insulating buck-board 3 is secured to-the back of the casing 2 and supports the switch parts. A pair of brackets 4 and 4 'are se-= cured to the back-board 3 and serve to support an insulating base 5 and coils (Sand '7. A U-shaped bracketsupport 8 is secured to the base 5,:1nd a switch arm 9 is pivotally the cas-' mounted between the sides ofthe bracket 3- by a pin 10.' A pair of-contact members-12' and 13 are mountedone at each end of'the; arm 9, and are adapted to engage-stationary input contacts 14 and 15, respectively,-secured at the-opposite ends of thebase The contacts 12 and 13 are held in position by a bolt 16 and spring-17,: which spring i mounted onthe bolt l6 betweenthe upper face .of theIcontacts and a. nut;18 tlireaded on tlieiboltii The springsl'kseriveitoitlensiori or press the contacts: 12:3118 13fiagiiinsbtliq stationary contacts 14* andZ-15m: til 9' $1? The coils i 6/ and: 7 are' zprovidedmvitli' hol low; or Ltubular; cores iofidnsulatin'g material 19 .:and;.l9 respectively; which eirtend iips pluxge'rt-membersefllaiandsi2ljcaregconnectedl to the arm-91 onsop positeasideof itsipivotail mounting/by a linkz an'einbersi.-22r'ggindi' 23fi esp ectively; !and-:- are mounted I ivithinithe- -tu bulan eorei neu'ibers: 19 and i9 .ofr-the eoilslso 3 as to? be.- attracted.ibyithercoils'i6, :7 when said coils are energized. .d v'

' Energi'zatiori ofucoil "6 will 'ialttracti the plunger 20 andficauseathiswitclb amii 9-16 roclriaboutei'ts spivot'andk engage the contact member 12 swith ztlieJ inpnti contact, 14',- wliile energizationa offitlie coil: i willlvattract itheplunger: i21sand cause::the'switcli ar ii91t i rock: aboutiits pivot thw'reverse direction' and: eng'zige tlie 'icontact ine nberfl'B twith lthe in ut, t tiilii 3.: "lgffliwfi i"; Pnirm The contacts 12 and 3:are4- conhedted by a flexible conductor 245-,- whichiiii turn 'ris connected to a." single outputvtei minal 25z 3511i;

pair of---switch--ariiis::26 and-1326 are pivotally :mountedn' on2 i a 'piri 27 below i the coils 6 .and 'li and carry bridge; contacts 28 and: 29, respectively; I at their free ends adapted tojbridge contacts 3 0-''31 33, respectively; when the respective' arnis are rocked t0WaId"-th8 'C0llS Thear-ins 26 and 26 are provided with small-tubularcore plungers 34 and 35,*respectively whichvpro ject upwardly within the 'cores 1 9-=and :19-" of the coils 6 and 7 and are adapted to be attracted by said coils 'when said -coils'are energized and thus rock saidswitch arms. A l-shaped bearing block-'36 is :Inounted on the lowe'r side of the switch :arm 9"- and is adapted to be engaged-by a spring-pressed Due to thl'i'gh't'weight of the core plung ers 34 and and the switch arms 2 6 and 26, coupled with the holding resistance of the ball 37 on the switch farm 9;.whenrtlre coils 6 and 7 are energized. the plungers 34 and 35 will be-the-first to -mov intothe coils and,therefore, the bridge pieces-28 and 29 will bridge'the contacts and-'32 33 prior to the-m0vement of the switch arm 9. a I Extension rods 39*and- 4O are s'ec'ured'to" the lower ends: of..the 'plungers 20-and 2l, respectively, and extend (low n-war'd'l y throu gh the plungers 34 and 35. llhe: lower ends of the rodsz39' and 40are threaded-Ito receive nuts 41 and ;re spectivellj*, andl bridge" plates 43- ;ands 44mm: slidabl-y mounted; on the rods 39 andl'oaaespeotively; aboiidithe' nuts 4b and 42 land are no'rihallylhe'ldiagdiiist the: nuts by: :t00lled1iSpllIlg9I 45! a'ndl 46; o The springs- 45%3Iitt'46 are: mounted around .cth rods 39 and A0 and- .ha vei their l'ower i ends bearing. against; the 1 plates -43'landue4owhilq their upper lands'bearflgaginstzpirih A7- and 48} -The1 ;bridge'; plates 1 43: land 4 ll'areeadapted to engage and bridgeiieont-ac'ts'i i4950 land; 51 52;'= respectively; whemtherplungers' 20 and-.21,3;respectixiel 'aieiattraeted by theircOils. lei-1 E'Jifj rn': ai -vii 11 11.! Now:;referring to Eiguife I 3': of s.the'idralwings; the; electricah! connectiohsnand control; features 1,01: the; switch rzwillf he :demnilied icm designates-.1 thegrtrolley {lpfole 'izsiourder of: su pply-eiwhichi is connected l tolthexifiPuhcom; tact;14;watnd-iB-.-designatesetheatrailing/cable; or.)extension;sourceiofzsupply whiehais com nejetetl f to ';the"ainput lcbntact 1i5.i)'; G ;(1Big;

nates a controller, and Miidesigiratesh-the moton zto;bea-operatedlaze 29mm; erli.

.A; power; line- 55 :,=lea'ds -irofi1:=the;ioutpht; terminali-25etoz the :controllefl-Qa and a power. line 56.-leads fromithco'nt-rollehto;one side of; the amotortM; i while }t)l1 :QtlheBL side or. the motonis groundedi'througha lin '57. {1 rlThejone 'lldiO;th eWiI1dlpg20 f!iCOll? 6 is connected by-a-line-58to them put contact: 14;;whilej the: other end- .i'sz-connectedto contaets-52and 33 by a linx59.::; :1; inc

Onerend of .the winding-lot: the-- coil'37. is: conneote'tdto; input contact; 15: by a line 60,; while .the other-:endis connected .to. contacts 49iand30-bya line 61; it; vi 3 Contactsl3l-rand are con'nected in series bya line. 62 and contacts 51 and 32areronnected-=-in series by" a-line 63. Contacts, 50 and 51 are connected in series with an inter- 65. The switch 64 closes the circuit to across the contafcts5l and 52.

. tacts l4 and 12 and connector 2% to output terminal 25, thence through line to the controllertC and from the controller through line 56 to motor M a nd thence through line 57 wto,v ground, -thus completing the motozcircuit.

Now assuming-that itis desired to operate the locomotive or other apparatus operated by the motor M from the trailing cable B-andas'suming that the trolley pole A has been removed from the trolley wire andthat thetrailing cable B has been placed on the trolley wire. \Vith-the elen'ients in this position,,curren't will flow from the trolley wire through the cable B, to the contact 15', then through line and coil 7 to line 61, and contact 49, across theibridge piece 43 to contact 50,-thenbe through line 65 and controller interlock-64 to-ground, thus cornpleting' a circuit through the coil 7, causing tlIQ COllT/T to attracfltheplungers"21 and Plunger 35 will. bethe first attracted'due to its weight and j=the mechanical holding n1echa nism oii thearmlfll retardingthe movement of the plunger 21. The, attraction ofplunger 35 :will op'erate theswitc'h arm.26 an l-.oause the platei29to1bridge contacts ,32' and 33. However, since;- the-trolley poleA: is removed from; the trolley-line, no circuit willbe com pleted bystheopera-tion of the switch armQG.

The attraction of the plunger 21 \yil lroclr theas'witch faring;- so: as to} engage contacts 13 and 15, completing a power circuit from the; cable iB -;-thro.ugh;th;e contacts- 13 land 15 and flexibleiconnectorg 24 to output terminal 25, thence through: Line -.55 to controller C, line, 56 to motor M and line 57 to ground,

It will, of course, be understood-th tgvhen the; Switch zarin =9y is rocked. by the attraction ofi theP Iun'ger 21, contacts 12 and liwill be separatedeand plunger-2O iwillg begraised soas to remove the bridge piece fronr-contacts 49ai1d 50;- a'nd-that the ball 37 will; engage the opposite face ofthe b'lo'ck 36 so as; to' mechanically-hold,the s\\'itch arm 9 in position. 7 .1

.iVlien fthe; plunger 2L is attracted, the bridge piece 44iiwill be lowered: to bridge Now assuming that; the cableB removed from othetrolley wire-and it is desired to operate thezmotor from the trolley pole A again, the trolley. pole- A is placed on the trolley line so that current will flow throughthe pole A to the input contact-l4, then through line 58 to coil 0, and line 59 to eontact 52, then through the bridge piece l2 Z! contact 51 and line 65 to controller interlock G t, and through the interlock O-l to luu lUb

ground, thus energizing the co'il .6 ;"-..=Ener gizationof. .the. coil; 6, will-attract, the vplungers and '34.. iPlunger34ciwill be the first to .berattracteddueito..its:small weight and the. mechanical holdingme'chanism-on the arm 9 retarding-the,movmei1t 'of-the plunger 20.:Qlhe-atti action of the plunger will operate; theswitch arm' 26 and cause the platez28 to. bridge contacts 30}. and 31.; However, since.tl1e:cable-.B'isu'emoved from the trolleyi-lin'e; no circuit will 2be completed, 1,

The attraction of the plunger 20; will rock the switch 'armr9 .so -a.s..to engage contactsl 12 and 14,: completing apower circuit from' the trolley .A through-the.contacts-12 and 1 4: and flexible connector 24K. to. it-he output-terminal I 25,- ;tlienoe through ,line .555 to" the: controller Lil wThe :operatiomof-,the switch iii-111.9 to'close the contacts iand.14;will,,-of course, dis engage-thacontacts l3 andw15n. If it;is attempteditozcutizovers tothe cable while the -.t-rolley?-pole- A is :still engagek'i with the:trolley =line,iaszgsoon as'the-cable B isiengaged Wl't-hgt-he trolley line, current will flew :from. the trolley'lineithrough the cable Bi ,to -1.contact and th en -.thro.ugh ;-line 560, coil g7; andzrlinelfila to. contact-.49, thence across/the ;bridgei.pie.cefi43 to -Tco'ntact50, then throughrlineaififi and controller: interlock-.54

' to..-ground-',ithus completing.a'icircuitzthrough thevcoil causingthe. E coil; 7 to; attractv the plungers 2Land 35;: I Due-wto. the lightweight ofthe plunger andathei resistaricepf-ihe mechanical holding mechanisnron the switch arm 9, the plunger 35 will be the first to be attractediatid; therefore, IsViiitchai'inQSfQWill be rocked to move the bridge plate 29 across the contacts 32 and 33. Immediately upon the bridging of contacts 32 and 33 a circuit will be completed from the trolley pole A to contact 14, then through the line 58, coil 6, and line 59 to contact 33, then through the bridge plate 29 to contact 32, and wire 63 to contact 51, and from the contact 51 through the line 65 and interlock 64 to ground, thus energizing the coil 6. Energizing the coil 6 will cause the coil 6 to attract the plunger 20 and, since the coils 6 and 7 and plungers 20 and 21 are balanced, the attraction of plunger 20 will balance the attraction of plunger 21 by the coil 7, and the switch arm 9 will remain stationary until the trolley pole A is removed, at which time the switch will operate to complete the circuits described above when the cable B is used instead of the trolley pole A.

Now assuming that an attempt is made to cut over to the trolley pole A while the cable B is engaged with the trolley line, as soon as the trolley pole A is engaged with the trolley wire, current will flow through the pole A to the contact 14 and then through line 58, coil 6, and line 59 to contact 52,

thence across the bridgepiece-4A- to contact 51,}then throughline 65.;and 'controller interlock G L-to grounjd, thus completing the circuit through the coil 6, and causing. .the coil 6 to attract? the plungers 20 and 34.. Due to the light; weight oftheplungerQ i and the resistance of ,the mechanical holding mechanism on the switcharmfi, the'plunger 34 w ill be the first t'o beattracted'and, there fore, switch arm 26 willbegocked togmove the ,bridge 28 ;across Fthe .contacts; 30 and 3l. Immediately; upon, the lbridgingi of contacts 30 and .31 a circuit will be; completed from the le ;B1 to nt ctthe thrqu h. 11 1 line- 30,. coil ,7 and li'ne.6l to contact f g-then ugh-the n g P t w. c n estslatwire '62 to contact 50,; and from-the contact 5Q; tl rough-1the lineHGS and interlock gr.ound,,ti1u energizing. the coil 7 ,Encrgiia; tion of .:the .,coil -7 ,will, cause theg coil ,at a -t zpl g if 2 a d. s nc h vi s; and- 7 and ,plungers 20 ,and 21 arebalanced as heretoforedes cribe d, the 1 attraction. ,of plunger, 21 will balance theattraction of the pIunger'QQ-by the'coil G-andthe switch arm 8 will remainstationary until: thecable B. is r em ov ed,;at which time the. switch will ,o perate' to transfer fromone source of current to'the'pther. g I If,when an attemptis made to. .ran ei or cut i v' ef m esoumei -cur zenqltapiil to; the other. in 1 anyot ,the above described instances, while .the controller-C, ,is on: Po i o t e i e oc .4 wil Ja .91 9? 5 n none of the aboveidescribed eontroL-circ ts ca e. omplete 5 hereby.tl aiive ylzp f t g: t e Q tt n'giQY a-fimm 91. source; a upp w ozhe iq hervwhile. dead $0 the motor M, that is until the controller C is in off position.

I claim 1. A cut-over switch having two input contacts, asingle rocking switch element movable into circuit closing relation with one or the other of said contacts, means for yieldably holding said switch element in circuit closing position, and operating means for said switch element including a pair of plungers and magnetic operating coils for said plungers, a control switch for controlling the energizing circuit to each of said coils, and operating means connecting each of said switches with the plunger operated by the coil controlled by the other switch,

whereby the attraction of either of said plungers by the coil associated therewith will operate to close the control switch to the other coil.

2. A cut-over switch having two input contacts, a single rocking switch element movable into circuit closing relation with one or the other of said contacts, mechanical means for yieldably holding said switch element in circuit closing position, and operating means for said switch element including a pair of plungersand magnetic o'per at-in'g-coi-ls for 'said 'plungers, a ooxitrol switch for controlling the ienergizing circuit to each of said coils,-'-'and operating means connecting each of said 'switches' nfith the plunger operated by -thecoil'--'controlled by the other switch, whereby the attraction of either of said plungers-by t-h'e eoi l aseoeiated therewith will operate to close fihe control switch to-the other coil.

3. A cut-over switch having; two i'npuit contacts, a switch element movablei iiito c'in cuit closing relation-witheither of 'saidoontacts, mechanical means for yillabljhold ing said switch element in circuit closi'n'g p0- sitlon, an electro jniagnetic; coil hakrii'ig bfle end of'its w'ind-ing 'connected td one of said input contacts, a-se'cbnd electro magnetic coii having one'end of its winding-connected to the other input contact, eaich of o'oils having the other" ends ofitheir wifidifi gs eonnected to" theground thtoiighjewitchem plungers connected to' said'swi*teii 7 element and said last named switches afid operativ l y associated with cone- 56% td-"51? "at-J ti'acted by said eoils' "'vlle'i'if'"fsz"1 id"*Eoilsre' energized and 1 adapted when attracted operate said switch element' aiid' saidq last named switches, said last named'switcl'iesl being adapted to be moved' intoeiflctiit closing position to close the; circuit iZ'G*tliQ' dQ'Dl"- gized coil upon the attractioii of siii d plu ng eis, a1 second 's'wiv'itch elenient operabie; by said "coils, said last named elemei tshaiving plungers adaptedto b ware-readily 'ifitract ed than saidfirst named pmngaiapsaid last named switch element? bein'g adapted wipe at tracted by either-oi the' coils imlfiediatlyi up:

on energization of said coils and to move into position to close the circuit through the deenergized coil priorto thevo'peration of said switches operable by said-first named pl ungers, whereby unless the input contact connected to-sa-id deenergized-coil is deenei'gized, said last named coil will immediate ly: become energized and its attraction force coupled w i th said mechanical holding means for said first named' switch element will maintain= said first/namedswitch element stationary.

h 'lhe combination with a -motor, a" controller-therefor; and two sources of current supply -to= said controller," of a cut-over vswitchwha ving twofingutcontacts; a switch element movable into'circdit' closing relation with either of' said contacts,- means for yieldably holding said switch element in *eircuit closing] position, and operating means for said switch =elementincludinga pair of plungers connected to said: switch element and magnetic operating f= coils for said plungers, control' switches -for controlling the energizing cireuit to each of said coils, operatingemea'ns nconnectingi each of said switches to the'ipl-ungei" operated by the coil cont-rollect-bythe other switch, whereby the attraction OfGiUlIGT of saidplungers by the coil associated =t/lre'rewith will operate to close the oontrol switchta the: otheif 'c0il, and means: associated with-"said controller for preventing the energization-of-either of said coils'= untilt sa-id controlleris in off position. In testimbny whereof, I have-hereunto signed my name.

a; LLtiiifJIiii-ALEXAN-DER' BROWN. 

